Electroweak Phase Transition in Georgi-Machacek Model

Understand

The Georgi-Machacek model extends the standard model Higgs sector by adding two isospin triplet scalar fields and imposing global SU(2)$_R$ symmetry on them.

• A feature of the model is that the triplets can acquire a large vacuum expectation value without conflicting with the current experimental bound on the $\rho$ parameter.
• We investigate the electroweak phase transition in the Georgi-Machacek model by evaluating the finite-temperature effective potential of the Higgs sector.
• The electroweak phase transition can be sufficiently strong in a large parameter space when the triplets acquire a vacuum expectation value of $O(10)$ GeV, opening a possibility to realize successful electroweak baryogenesis.